OTA

[socie]

We use nRF52832 on our product.
We need to update the application remotely in the field using smartphone with BT.
The unit in the field will already have an app running on it.
Also, there is no access using wired uart and access to reset button is possible.
Now looking through all apps and methods avaialble from Nordic, I cannot see anything suitable.
So, can you tell me when it comes to remote OTA program downloads, what is the best and easiest app to use ? And please let me know if we can do the above in the field ?

[cbd]

Have you looked at the DFU examples?

Its already too late for units in the field but for new units you'll need to program them with a bootloader that has BLE support. Rather than a button press you can use a secured characteristic field write and hand shaking to reset the unit and trigger the bootloader device firmware update cycle.

Obviously this will not only require the units being programmed with a suitable bootloader but also a version of the app that can handle the field write and reset the unit to trigger the dfu process.

[Bjørn Kvaale]

Great answer cbd! I would also add that the Secure DFU blog post is a great starting point. It explains all the steps needed to do a DFU using the nRF Connect for iOS or Android smartphone app. You can also try using the nRF toolbox application. The source code for nRF Connect is not available, but we do have the source code available for the Toolbox application (Android, iOS). You could either use the nRF Connect app directly or use the source code from nRF Toolbox as a starting point to create your own application.

We also have a buttonless DFU application, which shows you how you can enter the bootloader from the application without requiring a button to be pressed. More information on the buttonless DFU is also given in the blog post. 

Like cbd said, to be able to do a wireless DFU, you need a bootloader on the device in the field. If you do not have a bootloader on the device, you need to program the device via a cable, so it is unfortunately too late for the devices in the field.